Episode 8: Is hemp more sustainable than cotton?




Hemp, Cotton, Sustainability,



Welcome to the Fashion Unearthed podcast. If you need help navigating the fashion industry sustainably, you have come to the right place. I'm your host Belinda Humphrey and my hope is to simplify the fashion industry so that businesses can make the best decisions for people, planet and product.


Hello, and welcome to episode eight of the Fashion Unearthed podcast. Some of you might know my background is in apparel, product design and development. So even though it's usually been a part of my job, I actually enjoy keeping up with new developments and innovations. So today's topic really excited me. And if you enjoy reading about product innovation and inspiration, I've got a monthly newsletter where I share the things that I've either found joy in or been inspired by over the month. And you will also get my free download 10 sustainable switches which will give you 10 easy switches to help you design more sustainable product.


So onto today's topic. Today I'm talking about hemp, and researching if it's more sustainable than cotton. I really enjoyed learning more about this material, particularly because it intersects both conscious creation and a regenerative planet. While it's been around for a long time as a material it's been commonly talked about within fashion as a growing opportunity and I've watched a few things pop up in the news articles so I was interested to dig a little deeper and see what's changed and why there might be a growing case for using hemp as a material as opposed to cotton.


Firstly, let's clarify that the hemp I'm talking about is the variety of cannabis that has a low concentration of tetrahydrocannabinol THC. So low that it would not have any psychoactive effects. Now regulation differs on how much but generally hemp contains less than 1% of THC, whereas marijuana may contain upwards of 25%. THC in industrial hemp is limited to below 1% in New South Wales, South Australia and Queensland and 0.35% in other states and territories. It is classed as a bast fibre which means it's one of a number of natural fibres derived from the stems of plants such as flax, jute and stinging nettle.


Now let's rewind a little bit and get some history on hemp. It's actually a very old plant, with archaeological studies showing evidence of hemp fibre usage dating back to around 8000 bc in present day Turkey. During the Middle Ages, sea traders and explorers went on to use hemp fibre for rope and sails, with the word Canvas apparently deriving from Cannabis. In 1788, hemp seeds landed in Australia with the prisoners on the first fleet with a theory that convicts weren't sent to Australia because of space issues in the UK, but to establish hemp crops to decrease reliance on Russian suppliers. But that's a whole other episode. Either way, seeds were given as gifts to settlers to establish large hemp crops in the colonies.


All seem to be going well, but around the 1930s they was a US church propaganda film called reefer madness. Parents were warned marijuana would make their children sex crazed, violent, suicidal and insane. Much like today Australia looks to America and in 1938, an Australian newspaper called The Smiths Weekly ran the headline "New drug that Maddens victims" and described marijuana as an evil sex drug which caused users to behave like raving sex maniacs.


The article that I got that from with an ABC article and I'll link to it in the show notes. But it goes on to suggest other reasons why hemp was on the hit list of the government's. One being that the prohibitionists had prohibited alcohol and had to move on to something else otherwise they would be obsolete. The other being that hemp was a threat to cotton and nylon producers and with Egypt and Lebanon being big cotton producers, getting rid of cannabis got rid of hemp, and their competition.


That article was really interesting. And like I said, it will be in the show notes. But they also go on to say that the prohibition movement set hemp crops back about 100 years. And if that hadn't have happened, Australia would have the hemp industry today on par with many of its other major crops.


So what's changed? crucially, it took until the 2000s to distinguish between low THC hemp and cannabis. And from what I can see sustainability has fast tracked this crop back into the public, as well as an increasing awareness around improving conventional farming practices.


So much of what I've read and researched hemp is a really versatile product. But according to James Vosper, the president of the Australian Industrial hemp Alliance, "It's not a wonder crop that can replace everything and shouldn't be held to an unfair standard". He goes on to say "What we're saying is it's a viable alternative to cotton to wool to concrete. That's all we're saying." Even though it uses much less water than cotton, it still needs between three and six mega litres of irrigation per hectare, and it's nitrogen hungry in the first few weeks of growth.


That being said, it is an excellent crop for carbon sequestration, consuming four times as much co2 as trees do. It's also fast growing, faster than most weeds, making it less likely to need herbicides, and in turn, avoiding soil erosion making it safer for the people working on the farm.


It's fairly pest resistant and even more so if planted at a particular time. And it can be used to clean up contaminated sites to mop up things like gold, lead, cadmium, nickel, those sorts of chemicals from the soil. Also because it's fast growing, taking as little as 90 days to reach maturity, it allows two crops to be grown over a season. And because of this purifying quality and the ability to grow fast, many grain farmers are introducing hemp crops into crop rotation.


It also requires little land to cultivate, resulting in higher yields per hectare. Some sources saying double the fibre yield per hectare than cotton. In the Farmer Magazine, Australian farmer Bob Doyle reports that even though it requires a dose of nitrogen early on, when you harvest the fibre, up to 70% of those nutrients are returned to the soil via the organic matter left behind. Mr. Doyle also goes on to say that he has discovered benefits in rotating hemp crops with fodder crops like Lucern, reporting that "Our Lucern crops planted after hemp have a much higher yield because of the amount of organic matter that is returned to the soil and there is less need for weed control inputs".


Another benefit I came across was that hemp requires significantly less water than cotton with Citizen Wolf's website stating it requires 50% less water than cotton.


Over time, the fabric has been refined a lot so that hemp is no longer like hessian. I think we all remember or have sort of an instant visual when someone says hemp and you kind of picture literally a hessian bag. But innovation has evolved and there's now a process to make it more akin to a light and durable cotton. It can go through a mechanical process to create cottonised hemp fibre, which is almost indistinguishable from cotton and makes it suitable for spinning blends with cotton, wool, synthetic or semi-synthetic fibres. Levi's use this process in a collaboration with Outerknown to create a capsule collection in 2019.


So far, I think James Vosper was being a little bit modest in the potential of the crop and what it can add in terms of farming in the land. But let's look at some of the properties that sets it apart from other natural fibres.


Naturally thermo regulating it keeps you cool in summer and warm in winter. It is also highly resistant to ultraviolet light protecting you from UV rays, but also allowing it to not fade or disintegrate in sunlight. Based on SGS testing by WAMA underwear it was found that hemp fabric was 99.9% effective in blocking UVA and UVB rays, meaning it qualifies as a top tier UPS 50+ plus fabric. This along with being lightweight, weighing up to 1/3 less than wool or cotton makes it really suitable for active or outdoor garments, and even just the Australian lifestyle in general.


It's also one of the strongest and most durable natural textile fibres. Which if you remember back, it was originally used for ropes and sails, so it was pretty strong, people knew it was strong. It's been tested to have three times the tensile strength of cotton, and being more durable it allows it to remain in use for longer, up to two or even three times longer than a shirt made of cotton.


It absorbs moisture, preventing bacteria formation which in turn helps reduce bodily odours. Hemps moisture retention is 12%, linen is 10-12% and cotton is 8%.


I actually found it really hard to find a lot of negatives on the material, the one that I did find was that it's elastic recovery is quite poor less than linen. It stretches less than any other natural fibre, which probably makes sense if it is the strongest.


So all in all, there's good reason why hemp is gaining momentum and shaking off the outdated propaganda. But speaking from experience, it's been harder to find a consistent source in some of the quantities needed, which often lead to a higher price as well as demand was outstripping supply.


So I was particularly interested when I saw Ragtrader reporting that Australian label Afends had just bought a 100 acre property just outside of Byron Bay to serve as a hemp research and development hub to eventually be used for clothing. They're passionate about their community and want to help local farmers once they get the process right, with the ambitious goal of restarting the industry here in Australia.


So hopefully I've answered the question, "Is hemp more sustainable than cotton?" And I have to say from what I read, yes, it is and from what I see it could be a positive opportunity for Australian farmers too.


Let me know what you think, what has been your experience with using Hemp? Have you been thinking about it? You can DM me on Instagram or send me an email at info@belindahumphrey.com. As always, I'll put the links in the show notes over at belindahumphrey.com/podcast and if you're liking the podcast, I would love it if you took five seconds to either hit the stars or a little longer to leave a quick review. It really helps people like yourself find the podcast. Thanks so much for listening. See you next time! 


Thanks for listening to the Fashion Unearthed podcast. If you want to get in touch head over to belindahumphrey.com or you can find me on Instagram @belindahumphrey_


Disclaimer: Whilst every effort is made to ensure that information is accurate at the time of recording, much like the fashion industry itself, this information may change. 


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